Inbox member clean up

Editor assessment

The subject labels the work as inbox member cleanup, which is a category rather than a change, and the body's one line, deleting unused logic and tests, adds only a little: what the unused logic was and why it became dead code is left to the diff. Chore is the accurate type for the cleanup. No scope, no footers beyond Co-authored-by trailers. The trailing pull-request number is conventional. Hygiene is fine: short and period-free. Valid and honest, but it documents the category without the substance.